"""Job cost and time estimation from STL geometry."""
import math
import os

# g/cm³ per material
_DENSITY: dict[str, float] = {
    "PLA":   1.24,
    "PETG":  1.27,
    "ABS":   1.04,
    "ASA":   1.07,
    "TPU":   1.20,
    "Nylon": 1.14,
    "PC":    1.20,
}
_DEFAULT_DENSITY = 1.24

# Volume (cm³) at which MATERIAL_FACTOR applies exactly.
# Calibrated to Bambu Lab Studio: 26 cm³ lid → 50 % factor → 16.2 g (actual 16.24 g).
_REF_VOLUME = 25.0

# Factor change per decade of volume.
# Each 10× increase in volume → factor drops by this amount (models get fluffier).
# Each 10× decrease → factor rises by this amount (models get denser).
# 0.15 gives: 1 cm³ → +0.21, 250 cm³ → −0.15 relative to base.
_SIZE_SLOPE = 0.15


def _effective_factor(volume_ccm: float, base: float) -> float:
    """Scale material factor by model size using log-linear interpolation."""
    factor = base - math.log10(volume_ccm / _REF_VOLUME) * _SIZE_SLOPE
    return round(max(0.25, min(0.85, factor)), 3)


def estimate(volume_ccm: float, material: str | None) -> dict:
    """
    Returns a cost/time estimate dict for one job.

    MATERIAL_FACTOR (env, default 0.50):
      Base fraction of model volume that becomes filament, calibrated at
      25 cm³. Scaled up for small models (wall-dominated) and down for large
      models (infill-dominated). Approximate scale:
        ~1 cm³  → ×1.4  (tiny clip, almost all walls)
        ~25 cm³ → ×1.0  (reference — validated against slicer)
        ~250 cm³ → ×0.7 (large box, infill dominates)

    PRINT_SPEED_G_PER_HOUR (env, default 32):
      ~32 g/h matches Bambu Lab at normal quality; use ~20 for slower printers.
    """
    vat_rate      = float(os.environ.get("VAT_RATE", 19))
    price_per_kg  = float(os.environ.get("FILAMENT_PRICE_PER_KG", 15))
    base_factor   = float(os.environ.get("MATERIAL_FACTOR", 0.50))
    print_speed   = float(os.environ.get("PRINT_SPEED_G_PER_HOUR", 32))
    density       = _DENSITY.get(material or "", _DEFAULT_DENSITY)

    eff_factor    = _effective_factor(volume_ccm, base_factor)
    material_ccm  = volume_ccm * eff_factor
    weight_g      = material_ccm * density
    print_minutes = round((weight_g / print_speed) * 60)

    filament_cost  = weight_g / 1000 * price_per_kg
    after_misprint = filament_cost * 1.20
    net_price      = after_misprint * 1.30
    gross_price    = net_price * (1 + vat_rate / 100)

    return {
        "material_ccm":    round(material_ccm, 2),
        "weight_g":        round(weight_g, 1),
        "print_minutes":   print_minutes,
        "filament_cost":   round(filament_cost, 2),
        "net_price":       round(net_price, 2),
        "gross_price":     round(gross_price, 2),
        "vat_rate":        vat_rate,
        "price_per_kg":    price_per_kg,
        "material_factor": eff_factor,
        "print_speed":     print_speed,
    }